Phase-based electromagnetic surveys for geological formations

Patent metadata

Field	Value
Publication number	US-11150375-B2
Application number	US-201313742923-A
Country	US
Kind code	B2
Filing date	Jan 16, 2013
Priority date	Jan 16, 2013
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

An electromagnetic (EM) data acquisition method for a geological formation may include operating EM measurement devices to determine phase and amplitude data from the geological formation. The EM measurement devices may include at least one first EM measurement device within a borehole in the geological formation, and at least one second EM measurement device at a surface of the geological formation. The method may further include processing the phase data independent from the amplitude data to generate a geological constituent map of the geological formation, and identifying different geological constituents in the geological constituent map based upon the measured amplitude data.

First claim

That which is claimed is:

1. An electromagnetic (EM) data acquisition method for a geological formation, the method comprising:
operating a plurality of EM measurement devices in a borehole-to-surface (BTS) configuration or a surface-to-borehole (STB) configuration to determine phase and amplitude data from the geological formation, the plurality of EM measurement devices comprising at least one EM receiver and an array of EM transmitters;
inverting the phase data without the amplitude data to generate a geological constituent map of the geological formation; and
identifying the different geological constituents in the geological constituent map based upon the amplitude data, with reduced karst effect;
wherein operating the plurality of EM measurement devices comprises operating each EM transmitter of the array of EM transmitters sequentially to generate separate sets of the amplitude data, and wherein identifying the different geological constituents in the geological constituent map based upon the amplitude data comprises discarding one or more of the separate sets of the amplitude data that appear skewed and using one or more of a remainder of the separate sets of the amplitude data to identify the different geological constituents in the geological constituent map;
wherein a geological constituent is a fluid, wherein identifying the geological constituents includes identifying the type of fluid, wherein the type of fluid includes at least one of oil, gas, water, oil/water mixtures.

2. The method of claim 1 wherein the amplitude data corresponds to a resistivity of the geological formation; and wherein identifying comprises identifying the different geological constituents by comparing the amplitude data to reference resistivity data.

3. The method of claim 1 wherein the at least one EM receiver comprises an array of EM receivers.

4. The method of claim 1 further comprising determining in-ground amplitude data; and wherein identifying comprises identifying the different geological constituents further based upon the in-ground amplitude data.

5. The method of claim 1 , wherein inverting the phase data without the amplitude data to generate the geological constituent map of the geological formation includes separating regions of a reservoir, each region including a different geological constituent and wherein identifying the different geological constituents in the geological constituent map includes identifying the different geological constituent in each region.

6. A well-logging system comprising:
a plurality of EM measurement devices arranged in a borehole-to-surface (BTS) configuration or a surface-to-borehole (STB) configuration to determine phase and amplitude data from a geological formation, said plurality of EM measurement devices comprising at least one EM receiver and an array of EM transmitters; and
a processor to
invert the phase data without the amplitude data with at least one inversion algorithm to generate a geological constituent map of the geological formation, and
identify different geological constituents in the geological constituent map based upon the amplitude data, with reduced karst effect;

wherein each EM transmitter of the array of EM transmitters is configured to be sequentially operated to generate separate sets of the amplitude data, and the processor is configured to discard one or more of the separate sets of the amplitude data that appear skewed and to use one or more of a remainder of the separate sets of the amplitude data to identify the different geological constituents in the geological constituent map;
wherein a geological constituent is a fluid, wherein identifying the geological constituents includes identifying the type of fluid, wherein the type of fluid includes at least one of oil, gas, water, oil/water mixtures.

7. The well-logging system of claim 6 wherein the amplitude data corresponds to a resistivity of the geological formation; and wherein said processor identifies the different geological constituents by comparing the amplitude data to reference resistivity data.

8. A non-transitory computer-readable medium having computer-executable instructions for causing a computer to perform steps comprising:
for phase and amplitude data determined by a plurality of EM measurement devices in a borehole-to-surface (BTS) configuration or a surface-to-borehole (STB) configuration at a geological formation, inverting the phase data without the amplitude data with at least one inversion algorithm to generate a geological constituent map of the geological formation, wherein the plurality of EM measurement devices comprise at least one EM receiver and an array of EM transmitters; and
identifying different geological constituents in the geological constituent map based upon the amplitude data, with reduced karst effect
wherein each EM transmitter of the array of EM transmitters is configured to be sequentially operated to generate separate sets of the amplitude data, and wherein identifying the different geological constituents in the geological constituent map based upon the amplitude data comprises discarding one or more of the separate sets of the amplitude data that appear skewed and using one or more of a remainder of the separate sets of the amplitude data to identify the different geological constituents in the geological constituent map;
wherein a geological constituent is a fluid, wherein identifying the geological constituents includes identifying the type of fluid, wherein the type of fluid includes at least one of oil, gas, water, oil/water mixtures.

9. The non-transitory computer-readable medium of claim 8 wherein the amplitude data corresponds to a resistivity of the geological formation; and wherein identifying comprises identifying the different geological constituents by comparing the amplitude data to reference resistivity data.

10. The non-transitory computer-readable medium of claim 8 wherein identifying comprises identifying the different geological constituents further based upon in-ground amplitude data.

Assignees

• Schlumberger Technology Corp

Inventors

• Zhang Ping
• Cuevas Nestor
• Wilt Michael
• Chen Jiuping

Classifications

• G01V3/30 Primary

  operating with electromagnetic waves · CPC title